1. Field of the Invention
The present invention relates to coupler mechanisms for toy and model railway cars, or the like, and more particularly, to couplers utilizing magnetic means for coupling and uncoupling.
2. Prior Art
Toy and model railway cars utilize coupler mechanisms located at the ends of each car to affect the coupling and uncoupling of adjacent cars. Ordinary couplers mechanisms have been characterized by troublesome and unreliable operation giving rise to a need, especially with regard to the smaller scale model railroad couplers, for a simple inexpensive coupler which provides reliable coupling and uncoupling. Examples of conventional coupler mechanisms include the so-called "Arnold-type" shown in FIGS. 1 and 2, and a coupler mechanism disclosed in U.S. Pat. No. 3,840,127 to Edwards.
The "Arnold-type" coupler, generally referred to in FIGS. 1 and 2 by the reference character 10, includes a "C"-shaped coupler knuckle 11 secured to an end of a support shaft 12 and a flange 13 formed at and extending laterally outward of the other end of the shaft 12. The knuckle 11 includes a triangular formation 19 at its forward end having upper and lower inclined ramp surfaces. The flange end of the support shaft 12 is pivotally retained in a pocket 21 formed in a support means 15 secured to the end of the car 14 (broken line illustration). The flange 13 is resiliently urged by a helical coil spring 17, in compression, against a forward wall 18 of the support means 15. The knuckle 11 is mounted so that it may pivot in a vertical plane between a lower position substantially parallel to a trackway 20 and an upper position (FIG. 2) with the spring 17 resiliently urging the knuckle 11 to the lower position. In order to couple adjacent cars together, the cars are thrust towards one another causing one of the two knuckles to ride upwardly on the upper inclined ramp surface of the other knuckle. In the case shown in FIG. 2, the knuckle 11 is forced to its upper position by the upper inclined ramp surface of the knuckle 11'. The upwardly pivoted knuckle 11 then clears the horizontal knuckle 11' and is resiliently urged by the spring 17 to the lower position to engage the knuckle 11'. The cars may be readily uncoupled by providing a depending pin, 16 and 16', on each knuckle, 11 and 11', and an uncoupling means 22 which may be selectively caused to extend upward from the trackway 20 to contact one of the depending pins and force the associated knuckle to its upper position to disengage the knuckles and thereby uncouple the cars.
A disadvantage of the above described coupler is that the spring 17 can twist and thereby diminish the ability of the spring to maintain the knuckles 11 and 11' in their normal positions. As a result, the coupler operation is less than reliable. In addition, it has proven extremely difficult to control the running and stopping of the cars in such a manner to effect reliable uncoupling.
The coupling mechanism disclosed in the aforementioned Edwards' patent affixes a permanent magnet to the knuckle of a conventional coupler to provide a means for magnetically uncoupling cars. The permanent magnet is aligned on the knuckle with its polar axis along the vertical and with one pole facing downward toward a trackway. An uncoupling electromagnet is located beneath the trackway with a like pole on the trackway facing upwardly toward the downwardly facing pole of the knuckle magnet. The cars are coupled as described above for the "Arnold-type" coupler and may be uncoupled by selectively energizing the uncoupling electromagnetic to cause a resultant magnetic repulsion between the like poles of the magnets to pivot one of the knuckles to its upper position and thereby effect uncoupling. The direction of the lines of force between the two magnets varies as the coupler pivots upwardly, as a result, the repulsion force differs depending upon the relative position of the two magnets. This force variation makes smooth and reliable uncoupling uncertain.